In the past, film processors have included various means for threading a web of photographic material to be processed through a plurality of processing tanks which, for example, may include developer, a stop bath, fixer liquid and wash liquid. In one prior art processor dip or idler rollers have been mounted on elongated rods which pass through overhead guides and are progressively lowered into the respective tanks as the web is initially fed into the tanks during the threading process. Such a device was sold as the Williamson Processor by the Pako Corporation, assignee of the present invention. The Williamson unit proved to be relatively complicated although it has operated successfully for many years. The present invention is greatly simplified and substantially less expensive to manufacture than its predecessor. Instead of the slideable guide rods, each idler or dip roller is connected to one end of a flexible tape which passes over suitable guides and has a counterbalancing weight attached at the other end thereof. As each dip roller is progressively lowered into the tank, the weight on the other end of the tape is raised and when the roller reaches its predetermined operative position in the lower portion of the tank, the weight is elevated into engagement with a clutch engaging mechanism for actuating the next successive feed roller to cause the web to be fed downwardly into the next tank and lower the idler or dip roller therewith into its operative position.